I also bought that alternator. It came with the 2-belt pulley, which I then replaced with the original alternator's pulley. You must use washers to space the pulley properly as the ebay alternator pulley centerlines are not in line with the original 200tdi pulley.

It works perfectly though...good as new, and better than old. Tach signal through the w pin

Got the alternator in today. Fit like a glove. I didn't need to space anything out. The pulley sat right in line when I swapped it over. Here's a pic of the failure. Turns out the rear bolt wasn't in and I guess that put a lot of stress in the front one which being aluminum sheared right off. All three bolts are in now. Should be good to go!